Simultaneous determination of four sesame lignans and conversion in Monascus aged vinegar using HPLC method

Area of Science:

• Food Chemistry
• Analytical Chemistry

Background:

• Monascus aged vinegar contains bioactive sesame lignans like sesamol, sesamin, asarinin, and sesamolin.
• Understanding the impact of processing on these lignan levels is vital for quality control and health benefits.

Purpose of the Study:

• To develop and validate a high-performance liquid chromatography (HPLC) method for simultaneous determination of four key sesame lignans in Monascus aged vinegar.
• To investigate the effects of acid hydrolysis and various heating treatments on the content of these lignans.

Main Methods:

• Development and validation of a specific and accurate HPLC method for quantitative analysis.
• Application of acid hydrolysis and four different heating treatments (including autoclaving) to Monascus aged vinegar samples.
• Comparative analysis of sesame lignan content before and after treatments.

Main Results:

• HPLC method demonstrated high accuracy and specificity for simultaneous sesamol, sesamin, asarinin, and sesamolin determination.
• Both heating and acid hydrolysis promoted sesamin isomerization to asarinin and sesamolin decomposition to sesamol.
• Autoclaving (125°C, 15 min) maximized sesamol content, while acid hydrolysis (25°C, 15 min, natural pH) maximized asarinin content.
• Severe thermal processing led to a decrease in total sesame lignans.

Conclusions:

• Autoclaving and acid hydrolysis are effective methods for increasing sesamol and asarinin content in Monascus aged vinegar, respectively.
• The developed HPLC method provides a reliable tool for analyzing sesame lignans in aged vinegar.
• Processing conditions significantly influence the profile and quantity of bioactive sesame lignans in Monascus aged vinegar.